Science & Mathematics - 18 August 2007

compute arcos(- radical 3 / 2) and also ( -1/ radical 3)

2007-08-18 18:28:05 · 4 answers · asked by Anonymous in Mathematics

2007-08-18 18:25:58 · 2 answers · asked by teresa 1 in Chemistry

I have just started my geometry class last week. The first things I learned about were the point, line, and plane. According to my teacher the point has no size. None at all. Is this true, or is it just unimaginably small? I don't see how points can make up lines and planes if they have no size. Its like 0+0+0 and so on. It equals 0. How can they exist without size?

2007-08-18 18:21:04 · 9 answers · asked by Jack 2 in Mathematics

A block accelerated from rest by force along smooth incline for 5m until it clears the top of the ramp at speed 8m/s.
How can I find the highet elevation (h) above the x-axis for the block by by using this formula: V2=U2+2as?

2007-08-18 18:07:58 · 5 answers · asked by Ham J 2 in Physics

1. Three marbles are to be drawn successively from a bag that contains 4 white marbles, 2 red marbles, and 3 green marbles. (Note that the marbles are not replaced after they are drawn from the bag.) What is the probability that the first marble drawn is white and the second marble drawn is red and the third marble drawn is green?
a. 1/21
b. 1/63
c. 8/243
d. 8/729

2. Using the word "order" explain the difference between permutations and combinations.


3. Given a data set with a symmetric frequency distribution, a mean of 63, and a standard deviation of 3.
a. Approximately 68.3% of the data points are between 57 and 69.
b. Approximately 68.3% of the data points are between 60 and 66.
c. Approximately 95.4% of the data points are between 54 and 72.
d. Approximately 95.4% of the data points are between 60 and 66.

4. Give an example of a stratified sample

5. Give an example of a random sample.

2007-08-18 18:06:02 · 4 answers · asked by Gael C 1 in Mathematics

1. e^ln3x=11
2. e^x+4/ e^4=1
3. (e^4)3x=e^4e^3x
4. e(2lnx-ln(x^2-3x+1)=1
5. e^2x-2 * e(x+2) + e^4 = 0

2007-08-18 18:05:15 · 3 answers · asked by Anonymous in Mathematics

2007-08-18 18:04:01 · 2 answers · asked by Gideon 1 in Chemistry

What is the brain's processing speed?

2007-08-18 17:55:15 · 5 answers · asked by oblivion60 1 in Physics

2007-08-18 17:48:52 · 9 answers · asked by C00L GαL 2 in Mathematics

Can someone explain to me what resonance means without copying Wikipedia?

And why can singers break glass using his/her own voice?

Thanks.

2007-08-18 17:47:53 · 11 answers · asked by Anonymous in Physics

Three resistances having identical resistance r connected in parallel.The cell & the ammeter have negligiable resistance.With the switch open,the ammeter reads 0.6 A.What will be the ammeter reading when the switch is closed?

2007-08-18 17:42:33 · 4 answers · asked by Anonymous in Physics

I'm sure there's a good reason, but it seems to be a rather bad idea. Isn't burnung rubber bad? Serious answers only please.

2007-08-18 17:39:23 · 3 answers · asked by Steve5000 3 in Engineering

"x(x+2)+(x+2)"????
is it (x+2) (x) or something plzzz help

2007-08-18 17:36:51 · 10 answers · asked by BoboboboboO! 1 in Mathematics

In an early space shuttle mission, astronauts played with toys to show and study how the toys move and behave in microgravity. Does anyone know what mission that was or a link to video of the toys in space?

2007-08-18 17:36:03 · 3 answers · asked by LA TotiJoe 3 in Astronomy & Space

I know that it rains there alot but i didnt know if it storms real bad or if its just overcasts all of the time.

2007-08-18 17:33:41 · 8 answers · asked by Sophie Baby! 1 in Weather

2007-08-18 17:32:23 · 2 answers · asked by Andrea 1 in Astronomy & Space

2007-08-18 17:31:38 · 2 answers · asked by PS 1 in Astronomy & Space

i realy want to put solar panels on my house but im curious how many watts i can get per panel.

2007-08-18 17:24:07 · 5 answers · asked by Vincent Q 1 in Engineering

If the Sun emits deferents electromagnetics waves besides the ones includes in the visible ligth spectrum, why can we just see the visible spectrum and no others electromagnetics waves emited by the sun

2007-08-18 17:15:44 · 9 answers · asked by chess_e4_pr 1 in Astronomy & Space

if 1.15 = one and a quarter hours
and 1.5 = one and a half hours
and 1.75 = one and three quarters hours
How do i figure out what's in between those fractions I realize that theres 15/15ths in a quarter so it there was a value of 1hr and 25 minutes how would i write that in the above terms.

I am sooo bad at math. Thanks!

2007-08-18 17:12:04 · 5 answers · asked by shadow_3211 2 in Mathematics

2007-08-18 17:07:41 · 6 answers · asked by Sporadic 4 in Astronomy & Space

An object with mass m and speed v explodes into two pieces, one three times as massive as the other; the explosion takes place in gravity-free space. The less massive piece comes to rest. How much kinetic energy was added to the system?

2007-08-18 17:05:12 · 3 answers · asked by physics maniac 2 in Physics

How much does an average lighting bolt weigh?

2007-08-18 17:02:37 · 5 answers · asked by cal 1 in Physics

Let's just say I (or you or whoever) make a group of people laugh -- they would probably all be focusing on you and directing positive energy toward you. People generate energy and can direct and sense it.

Is there a way that one could absorb this energy effectively, or does it just happen naturally, or is it not possible to do?

Odd question I realize and I wouldn't be surprised if I got no answers but I said I'd throw it out there anyway and see.

2007-08-18 17:01:03 · 7 answers · asked by Lanky Larry lol 1 in Physics

There's this one problem on the textbook that I don't understand...Thanks!
Suppose a given triangle is directly congruent to its mirror image. We can be sure that this triangle is? 1. Equilateral 2. Isosceles 3. Acute 4. Obtuse. And could u plz explain the answer too? Thanks!

2007-08-18 16:58:16 · 7 answers · asked by Anonymous in Mathematics

2007-08-18 16:57:58 · 6 answers · asked by Anonymous in Chemistry

The answers to the Universe

By Michael Gonzalez




There are vertical and horizontal Lines that make up our known Universe. Together they are known as the fabric of time and space. They all run at the speed of light never making contact with each other. Time can be defined as the movement of these lines in space. They carry light among many other things and can go through all objects. But not all that they carry can go through those objects. Light can get tangled up between these lines and travel with them, not being able to pass through objects they bounce off tingling our visual senses and enabling us to detect the object. Any object can warp these lines, but only at it edges and only ever so slightly. When these lines warp around a large object we feel it as Gravity. Magnetism is also an effect of warping these lines. These lines have different sets of laws of physics not understood by scientist, but there getting there. What we know as dark mater is these lines present in the vacuum of space and dark energy is what these lines contain. The collective energy of these lines can move a galaxy at almost the speed of light. And the collective mass of these lines can account for everything else that might seem missing in the UNIVERSE.


Oh how stupid of you, not to have thought of it yourself..!

2007-08-18 16:57:30 · 1 answers · asked by gone 2 in Physics

An ideal spring has a compression force constant of 40 N/m.
a) Use the grid provide to draw a force-compression graph for the spring.
Ok so the x-axis says Compression (m) and has 0, 0.1, 0.2, 0.3 and 0.4.
The y-axis has Force(N).
I used F = kx to get the following coordinates:
(.1,4)
(,2,8)
(.3,12)
(.4,16).
Is that right?
b) Use the graph to determine how much work is done in compressing the spring from
i) 0.0 to 0.1m
ii) 0.1 to 0.2m
OK so if u use W = Fx,
then you get for i) W = 0.1 x 4 = .4 J
But if u work it out like this:
Us = 1/2 kx^2, u get something else:
1/2 x 40 x .1^2
= .2 J?
So which equation is correct? I'm assuming my teacher wants me to use the first equation, because she specifically says 'Use the graph to determine...' but is it right? Why don't the two equations match up???

If u could explain the concept and why I'm getting it wrong, that would be great thanks!!

2007-08-18 16:54:11 · 5 answers · asked by Anonymous in Physics

A 6000 kg spaceprobe moving nose-first toward Jupiter at 100 m/s relative to the sun fires its rocket engine, ejecting 80kg of exhaust at a speed of 250 m/s relative to the spaceprobe. What is the final velocity of the probe?

2007-08-18 16:52:30 · 1 answers · asked by physics maniac 2 in Physics

What are the northern lights?
When, where, and why can we see them?
Are they real or an illusion?
If they are real, how far away are they?

2007-08-18 16:44:55 · 7 answers · asked by amy 1 in Astronomy & Space